fix findController for non-dart elements

pkg/polymer/test/event_controller_test.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library polymer.test.event_controller_test;
+
+import 'dart:async';
+import 'dart:js';
+import 'dart:html';
+import 'package:polymer/polymer.dart';
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_config.dart';
+
+var clickButtonCount = 0;
+var clickXDartCount = 0;
+var clickXJsCount = 0;
+
+@CustomTag('x-dart')
+class XDart extends PolymerElement {
+  XDart.created() : super.created();
+}
+
+@CustomTag('x-controller')
+class XController extends PolymerElement {
+  XController.created() : super.created();
+  clickButton() {++clickButtonCount;}
+  clickXDart() {++clickXDartCount;}
+  clickXJs() {++clickXJsCount;}
+}
+
+main() => initPolymer().run(() {
+  useHtmlConfiguration();
+
+  setUp(() => Polymer.onReady);
+
+  test('native element eventController is used properly', () {
+    var controller = querySelector('x-controller');
+    var button = controller.shadowRoot.querySelector('button');
+    new JsObject.fromBrowserObject(button)['eventController'] = controller;
+    button.remove();
+    querySelector('body').append(button);
+
+    button.click();
+    expect(clickButtonCount, 1);
+  });
+
+  test('dart polymer element eventController is used properly', () {
+    var controller = querySelector('x-controller');
+    XDart xDart = controller.shadowRoot.querySelector('x-dart');
+    xDart.eventController = controller;
+    xDart.remove();
+    querySelector('body').append(xDart);
+
+    xDart.click();
+    expect(clickXDartCount, 1);
+  });
+
+  test('js polymer elements eventController is used properly', () {
+    var controller = querySelector('x-controller');
+    var xJs = controller.shadowRoot.querySelector('x-js');
+    new JsObject.fromBrowserObject(xJs)['eventController'] = controller;
+    xJs.remove();
+    querySelector('body').append(xJs);
+
+    xJs.click();
+    expect(clickXJsCount, 1);
+  });
+});